Add the interface from two commits ago

src/fspp/impl/Filesystem.h

@@ -0,0 +1,40 @@
+#pragma once
+#ifndef FSPP_IMPL_FILESYSTEM_H_
+#define FSPP_IMPL_FILESYSTEM_H_
+
+#include <boost/filesystem.hpp>
+#include <memory>
+#include <sys/stat.h>
+#include <sys/statvfs.h>
+
+namespace fspp {
+class Filesystem {
+public:
+  virtual ~Filesystem() {}
+
+  virtual int openFile(const boost::filesystem::path &path, int flags) = 0;
+  virtual void closeFile(int descriptor) = 0;
+  virtual void lstat(const boost::filesystem::path &path, struct ::stat *stbuf) = 0;
+  virtual void fstat(int descriptor, struct ::stat *stbuf) = 0;
+  virtual void truncate(const boost::filesystem::path &path, off_t size) = 0;
+  virtual void ftruncate(int descriptor, off_t size) = 0;
+  virtual int read(int descriptor, void *buf, size_t count, off_t offset) = 0;
+  virtual void write(int descriptor, const void *buf, size_t count, off_t offset) = 0;
+  virtual void fsync(int descriptor) = 0;
+  virtual void fdatasync(int descriptor) = 0;
+  virtual void access(const boost::filesystem::path &path, int mask) = 0;
+  virtual int createAndOpenFile(const boost::filesystem::path &path, mode_t mode) = 0;
+  virtual void mkdir(const boost::filesystem::path &path, mode_t mode) = 0;
+  virtual void rmdir(const boost::filesystem::path &path) = 0;
+  virtual void unlink(const boost::filesystem::path &path) = 0;
+  virtual void rename(const boost::filesystem::path &from, const boost::filesystem::path &to) = 0;
+  virtual std::unique_ptr<std::vector<std::string>> readDir(const boost::filesystem::path &path) = 0;
+  virtual void utimens(const boost::filesystem::path &path, const timespec times[2]) = 0;
+  virtual void statfs(const boost::filesystem::path &path, struct statvfs *fsstat) = 0;
+};
+
+}
+
+
+
+#endif